1. Field of the Invention
The present invention generally relates to modified pigments, to methods of forming modified pigments, and to inkjet ink compositions comprising modified pigments.
2. Description of the Related Art
With increased reliance on personal computers, consumption of printing supplies, such as paper and ink, has risen. In addition, the introduction of digital photography has motivated consumers to print pictures, further increasing consumer interest in printing supplies.
To meet the demand for printing, manufacturers have turned to various printing technologies, including laser printing and ink-jet printing. Laser printing typically relies on a dry pigment particulate that is motivated onto a media, such as paper, through electrostatic forces and subsequently heated to adhere the pigment to the paper in the desired pattern. Ink-jet printing and related printing technologies typically rely on liquid suspensions including dispersed pigment particulate. With ink-jet printing, the liquid suspension is typically motivated onto a media through micromechanical or thermal processes. Once the liquid suspension contacts the media, the liquid portion typically evaporates or disperses in the media, leaving particulate pigment in a desired pattern.
However, printing quality, such as resolution and cleanliness of a printed article, can decrease as a result of pigment agglomeration or an unstable suspension. For example, pigment agglomeration can reduce resolution and result in pigment being placed in unintended locations during laser printing processes. Similarly, pigment agglomeration or failure of the pigment particulate to remain dispersed in a suspension can result in pigment placement in undesired locations and thus, a degradation of image quality. In particular, pigment agglomeration or poor dispersement of pigment can clog printer heads, can produce unwanted spots in printed images, or can produce unwanted lines or blurred text.
As such, manufacturers of inks have turned to modified pigments. While such pigments have provided ink compositions having improved properties, these methods may be costly and may result in low levels of surface modification. Therefore, there is a need for improved methods of forming modified pigments.